/*
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 *    RandomizableMultipleClassifiersCombiner.java
 *    Copyright (C) 2004 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.classifiers;

import weka.core.Option;
import weka.core.Randomizable;
import weka.core.Utils;

import java.util.Enumeration;
import java.util.Vector;

/**
 * Abstract utility class for handling settings common to randomizable meta
 * classifiers that build an ensemble from multiple classifiers based on a given
 * random number seed.
 * 
 * @author Eibe Frank (eibe@cs.waikato.ac.nz)
 * @version $Revision: 1.4 $
 */
public abstract class RandomizableMultipleClassifiersCombiner extends
		MultipleClassifiersCombiner implements Randomizable {

	/** for serialization */
	private static final long serialVersionUID = 5057936555724785679L;

	/** The random number seed. */
	protected int m_Seed = 1;

	/**
	 * Returns an enumeration describing the available options.
	 * 
	 * @return an enumeration of all the available options.
	 */
	public Enumeration listOptions() {

		Vector newVector = new Vector(2);

		newVector.addElement(new Option("\tRandom number seed.\n"
				+ "\t(default 1)", "S", 1, "-S <num>"));

		Enumeration enu = super.listOptions();
		while (enu.hasMoreElements()) {
			newVector.addElement(enu.nextElement());
		}
		return newVector.elements();
	}

	/**
	 * Parses a given list of options. Valid options are:
	 * <p>
	 * 
	 * -B classifierstring <br>
	 * Classifierstring should contain the full class name of a scheme included
	 * for selection followed by options to the classifier (required, option
	 * should be used once for each classifier).
	 * <p>
	 * 
	 * -S num <br>
	 * Set the random number seed (default 1).
	 * <p>
	 * 
	 * @param options
	 *            the list of options as an array of strings
	 * @exception Exception
	 *                if an option is not supported
	 */
	public void setOptions(String[] options) throws Exception {

		String seed = Utils.getOption('S', options);
		if (seed.length() != 0) {
			setSeed(Integer.parseInt(seed));
		} else {
			setSeed(1);
		}

		super.setOptions(options);
	}

	/**
	 * Gets the current settings of the classifier.
	 * 
	 * @return an array of strings suitable for passing to setOptions
	 */
	public String[] getOptions() {

		String[] superOptions = super.getOptions();
		String[] options = new String[superOptions.length + 2];

		int current = 0;
		options[current++] = "-S";
		options[current++] = "" + getSeed();

		System.arraycopy(superOptions, 0, options, current, superOptions.length);

		return options;
	}

	/**
	 * Returns the tip text for this property
	 * 
	 * @return tip text for this property suitable for displaying in the
	 *         explorer/experimenter gui
	 */
	public String seedTipText() {
		return "The random number seed to be used.";
	}

	/**
	 * Set the seed for random number generation.
	 * 
	 * @param seed
	 *            the seed
	 */
	public void setSeed(int seed) {

		m_Seed = seed;
	}

	/**
	 * Gets the seed for the random number generations
	 * 
	 * @return the seed for the random number generation
	 */
	public int getSeed() {

		return m_Seed;
	}
}
